21. The producers of packaged products argue strongly against changing sizes of packages to contain even weights and volumes, but no one in the trade comments unfavorably on the huge costs incurred¹ by endless changes of package sizes, materials, shape, art work, and net weights that are used for improving a product’s market position.
[参考译文]生产包装产品的商家极力反对在改变了包装上原有分量的商品，但他们却丝毫不反对为了扩大产品的市场优势，用于不断改变包装的大小、用料、形状、制作工艺以及商品的净重的大笔花费。

22. If the bottom half can’t effectively staff the processes that have to be operated, the management and professional jobs that go with these processes will disappear.
[参考译文]如果生产工人不能有效地完成有关的生产过程，那么，与这些过程相关的管理和专业职位亦将不复存在。

23. The biographer has to dance between two shaky positions with respect to the subject.
全句的字面意思是：传记作家不得不在与传主所处的摇摆不定位置之间跳来跳致病去。
隐含之义为：传记作家必须与传主保持适当距离，并要时常调整与传主间的距离。

24. In book promotions², the “unauthorized” characterization usually suggests the prospect³ of juicy gossip that the subject had hoped to suppress.
[参考译文]推销书时，未经授权的传记往往意味着读者有可能从中读到传主不希望公之于众的，绘声绘色的内幕故事。

25. In Japan, however, where babies are carried on their mother’s back, infants do not acquire as much attachment⁴ to eyes as they do in other cultures.
[参考译文]然而，在日本，由婴儿从小背在母亲背上，他们对眼睛的依恋就不如生长在其他文化环境中的孩子那样深。

26. Just how critical this eye maneuvering⁵ is to the maintainance of conversational⁶ flow becomes evident when tow speakers are wearing dark glasses…
[参考译文]当谈话双方戴着墨镜时，双方的目光接触在保持交谈顺利进行方面的重要性就不言而喻了。

27. Unlike other lawbreakers, who must leave the country, commit suicide, or go to jail, computer criminals sometimes escape punishment, demanding not only that they not be charged but that they be given good recommendations and perhaps other benefits.
[参考译文]其他的违法者或者逃亡国外，或者自杀，或者进监狱，计算机犯罪分子却不同，他们可以逃避惩罚，并且要挟不要指控他们，甚至还要求为他们出具有利的推荐信或者为他们提供其他好处，他们的要求往往能够得到满足。

28. The possibility of increases in the cost of uranium（铀）in addition to the cost of greater safety provisions could price nuclear power out of the market.
[参考译文]用于采取进一步的安全措施的费用加上铀价的上涨会使核能因价格过高而失去市场。

29. Having weighed up the arguments on both sides, it seems there are good economic and ecological⁷ reasons for sources of energy other than unclear power.
[参考译文]权衡核能赞成者和反对者的论据之后，从经济和生态两方面考虑，似乎有充分的理由认为应选用其他能源。

30. Clothes play a critical part in the conclusions we reach by providing clues to who people are, who they are not, and who they would like to be.
[参考译文]人们的穿着能够暗示他们是什么样的人，不是什么样的人，或可能会是什么样的人，因此，在我们判断一个人时起着关键作用。